1. Documented diagnosis of idiopathic/de novo MDS or non-proliferative chronic myelomonocytic leukemia (CMML), according to WHO criteria (white blood count, 13,000/uL), that meets International Prognostic Scoring System (IPSS) classification of low or intermediate-1 risk disease as determined by microscopic and standard cytogenetic analyses of the bone marrow and peripheral complete blood count (CBC) obtained during screening.